Abstract: Olefins having from 2 to 8 carbon atoms are hydroformylated in a process in which (i) an olefin-containing feed in which a proportion of a saturated hydrocarbon having from 2 to 8 carbon atoms is present and also carbon monoxide and hydrogen are fed into a reaction zone and reacted in the presence of a hydroformylation catalyst, (ii) a stream consisting essentially of unreacted olefin and saturated hydrocarbon is separated off from the output from the reaction zone, (iii) the stream is separated into an olefin-enriched fraction and an olefin-depleted fraction by rectification, and (iv) at least part of the olefin-enriched fraction is recirculated to the reaction zone.

Abstract: The invention relates to a process for the preparation of saturated C3-C20-alcohols in which a liquid hydrogenation feed comprising at least one C3-C20-aldehyde is passed over a bed of a hydrogenation catalyst in the presence of a hydrogen-containing gas, which comprises adding to the hydrogenation feed an amount, homogeneously soluble therein, of a salt-like base. The addition of base suppresses side reactions, such as acetalization, aldolization, Tischtschenko reaction or ether formation.

Abstract: Olefins having from 2 to 8 carbon atoms are hydroformylated in a process in which (i) an olefin-containing feed in which a proportion of a saturated hydrocarbon having from 2 to 8 carbon atoms is present and also carbon monoxide and hydrogen are fed into a reaction zone and reacted in the presence of a hydroformylation catalyst, (ii) a stream consisting essentially of unreacted olefin and saturated hydrocarbon is separated off from the output from the reaction zone, (iii) the stream is separated into an olefin-enriched fraction and an olefin-depleted fraction by rectification, and (iv) at least part of the olefin-enriched fraction is recirculated to the reaction zone.

Abstract: The invention relates to a process for the preparation of saturated C3-C20-alcohols in which a liquid hydrogenation feed comprising at least one C3-C20-aldehyde is passed over a bed of a hydrogenation catalyst in the presence of a hydrogen-containing gas, which comprises adding to the hydrogenation feed an amount, homogeneously soluble therein, of a salt-like base. The addition of base suppresses side reactions, such as acetalization, aldolization, Tischtschenko reaction or ether formation.

Abstract: Olefinically unsaturated compounds are hydroformylated continuously, the olefin being passed into the lower region of the reactor, under from 1 to 40 bar and at from 50.degree. to 140.degree. C. with the aid of a rhodium complex as a catalyst in a hydroformylation reactor having a liquid reaction zone which occupies about 60-85% of the reactor volume, the gaseous products and reactants being removed from the hydroformylation reactor, the products being isolated and the major part of the remaining gas being recycled to the reactor by the cycle gas method, by a process in which from 20 to 80% by volume of the cycle gas is fed into the hydroformylation reactor above the liquid reaction zone and/or below the liquid surface in the top fourth of the liquid reaction zone.

Abstract: The formation of an emulsion when working up reaction mixtures containing butyraldehydes and cobalt is avoided by a treatment with gases containing molecular oxygen in an aqueous acid medium at an elevated temperature, at least twice the amount of molecular oxygen stoichiometrically required for the oxidation of the cobalt being used per gram atom of cobalt present in the oxoreaction mixture.